Help me pull a decent espresso shot with Rancilio Silvia please?

Beginner and pro baristas share tips and tricks.
suolin

Postby suolin » Jul 05, 2019, 12:40 pm

Hi all,

I'm very much struggling to pull a proper shot (like you'd get at a very good coffeeshop) with my Rocky + Silvia v3 combo and was hoping you kind folks could provide some insight as to what I could be doing wrong. For the life of me I can't figure it out.

Equipment:
- Silvia v3 (no PID mod)
- Rocky doserless
- Rancilio naked portafilter
- VST 18g basket
- Espro calibrated tamper
- Fresh Mexican Chiapas medium roast beans (older than 2-3 days but under the 3 week mark)

What I do:
- Heat up the Silvia for a good 30-60 with the portafilter in.
- Remove pf, wipe the inside and grind exactly 18 grams of coffee into it with the rocky set to 8. Its true 0 is around 2-3, so the actual number is about 5-6.
- Whack the pf on wooden counter to try and settle the grinds.
- Tamp til it clicks, 90 degree twist, light knock and clean the basket edge if necessary.
- Very briefly run water through group head without PF attached (1/4-1/2 second) to make sure it's not too hot (my benchmark being, if steam comes out it's too hot and I cycle the water on/off a few times until I stop getting steam). If I let the machine heat up for the full hour I don't need to do this for my first shot.
- Attach pf and pull 25 second shot.
- Shots typically starts off as 2 distinct streams that merge dead center of the basket within 1 second or so (haven't been paying attention to this 100%, will keep an eye on it going forward).

What's wrong/what I am unsure about:
- The coffee always pours too fast and is too sour (never too bitter). The cup is fully filled by the 20-22 second mark.
- Needless to say there is never any tiger striping.
- The group head screw always leaves an indent in the puck, not sure if this is an issue but as far as I know the head is not supposed to touch the grind.
- Channeling occurs 1/3-1/4 times.
- The coffee clumps a bit when it comes out of the grinder. I already feel 8 on the Rocky is very fine but since it extracts too fast I should go even finer?

Any insight would be greatly appreciated.

Edit: added info re coffee stream on the bottom of the basket.

JRising

Postby JRising » Jul 05, 2019, 4:54 pm

The knock after tamping. Do you mean you're banging the portafilter on the counter after tamping? This could be the early channeling issue you're seeing. After tamping and looking at the grounds to be sure it looks alright, handle the portafilter carefully and try not to knock it on anything as this could cause the "sedimentary rock" of tamped grounds to form a fissure that could expand and allow the channeling.

And you probably have tried the simplest dialing in method of intentionally grinding too fine so that you ensure that it completely chokes off all flow, then dialing back slightly coarser in steps drawing test shots in between to get to that 24 second ristretto from which you can vary 1 parameter at a time to observe the effect.

Lastly, a Silvia is a tough little machine made with better than average parts, but it isn't very thermally stable. Even if you draw 2 great shots in a row, there's no guarantee that the next will be the same even if you've changed nothing, The pump's output changes audibly when the thermostat kicks on and off and you've already pointed out noticing how you need to check the water to see if it's too high above boiling. Don't be hard on yourself, if you get a lot of great espresso out of it, you're probably not doing anything wrong.

tracer bullet

Postby tracer bullet » Jul 05, 2019, 9:05 pm

I'd try a touch less coffee or buy a bigger basket if your'e seeing an imprint of the screen above.

Give a visual check to be sure the screen isn't filthy on the backside and causing water to come out unevenly.

Consider a needle of some sort to stir the grinds around to level them out and skip the whacking. Stir to distribute evenly then tamp. Look up "WDT" for some ideas.

I think if you can start with a more even puck and water flowing to it, you'll get better coffee and can next work on temperatures. You have to at least get the flow right before you can move on.

Don't discount the coffee itself either, make sure it's not too old and if needed just move on to a new bag.

Jasper_8137

Postby Jasper_8137 » Jul 05, 2019, 10:03 pm

Maybe a grinder issue. I really struggled with my Rocky - it always seemed that my grind was too coarse or too fine due to the stepped adjustment.

Espresso_Junky

Postby Espresso_Junky » Jul 06, 2019, 11:28 am

Have had a Silvia a bit over 2.5 years and have done well over 5,000 doubles with it. Great machine, but I strongly suggest switching out the factory shower screen/hex head bolt for this... https://www.amazon.com/Shower-Screen-Up ... B01NAAJRH1 When I first got my machine (used) it had the dinky OEM 14 gram basket and between that and the factory screen/huge bolt head it was always fracturing the puck because I like to updose, always have. I switched to Rancilio's OEM 18 gram basket and the flat screen conversion kit and the puck fracturing/channeling instantly disappeared.

Don't be afraid to grind finer as some coffees depending on origin/roast level/age post roast need to be coarser/finer at times. Numbers on a grinder are just for reference.

suolin

Postby suolin » Jul 06, 2019, 1:05 pm

Thank you all for your input. Here are some updates/replies based on what was suggested:

JRising wrote:The knock after tamping. Do you mean you're banging the portafilter on the counter after tamping?

Slight nudge on the side of the pf with the tamper to disloge any untamped grinds. Since I switched over to the VST basket (used to have an OEM 18g rancilio one just a week ago) I haven't seen that much channeling.

JRising wrote:And you probably have tried the simplest dialing in method of intentionally grinding too fine so that you ensure that it completely chokes off all flow[...]

Didn't do this as I'm worried about the machine sucking up grinds as part of the choke (I recall reading about it many years back). Is this not a concern?

JRising wrote:Don't be hard on yourself, if you get a lot of great espresso out of it, you're probably not doing anything wrong.

That's the issue though, what I'm getting isn't even good :( Borderline undrinkable. I don't even need great, just good would do.

tracer bullet wrote:I'd try a touch less coffee or buy a bigger basket if your'e seeing an imprint of the screen above.

I have to go down to a 13-14g grind to do that. I think I will have to follow Espresso_Junky's suggestion below to get rid of the screw imprint.

tracer bullet wrote:Give a visual check to be sure the screen isn't filthy on the backside and causing water to come out unevenly.

Looks solid.

tracer bullet wrote:Consider a needle of some sort to stir the grinds around to level them out and skip the whacking. [...]

Don't discount the coffee itself either, make sure it's not too old and if needed just move on to a new bag.

Trying the needle method now with a new bag of beans.

Jasper_8137 wrote:Maybe a grinder issue. I really struggled with my Rocky[...]

Absolute worst case scenario... I really don't want to spend on a new grinder.

Espresso_Junky wrote:I strongly suggest switching out the factory shower screen/hex head bolt for this... https://www.amazon.com/Shower-Screen-Up ... B01NAAJRH1

I have yet to see a fractured puck but at this point I'm happy to try anything. And to be fair, since I switched over to the VST basket (used to have an OEM 18g rancilio one before) I haven't seen much channeling.

Espresso_Junky wrote:Don't be afraid to grind finer as some coffees depending on origin/roast level/age post roast need to be coarser/finer at times. Numbers on a grinder are just for reference.

I'm starting to think the rocky is the issue and that saddens me greatly. I'm now grinding at just a couple of steps past true zero and the flow is still too rapid. I disassemble and clean the grinder once or twice a year at most since I probably do 1lb of coffee every 2 weeks.

Espresso_Junky

Postby Espresso_Junky » Jul 06, 2019, 1:39 pm

Could need new burrs to revive it to like-new again. The Rocky is quite capable as I was quite satisfied with the one I did have until a week ago.

myso

Postby myso » Jul 06, 2019, 6:56 pm

I second the advise to get a flat shower screen screw instead of the bolt type.
For prep, I think a funnel is highly useful to me. I made funnnels using paper cups, yogurt cups etc and now I use a steel one that sit on the rim of the basket. I always did wdt (formerly with toothpick and now) with home made londinium distribution tool replica (I used 0.7mm thickness copper cable, and made loops using a 4mm shaft).
Grind in the basket, distribute the grinds evenly using the tooth pick/tool. Lightly tap to the sides of the portafilter with your palms to level the grinds before tamping. For tamping don't put emphasis on tamping force but level tamping. For that I suggest putting 3 finger tips on the base of the tamper and feel that your finger is evenly distant against the rim of the portafilter basket. Tamp until it stops moving without exerting too much force (something that's easy on your wrist).

If you see grinds on the side walls or if the tamper has much free play in the basket I would suggest to get a 58.5 mm tamper and replace the 58mm one (if that's the case). Till than you can try NSWE tamping.

After tamping try the nickel test to see if your dose is less than the allowable max according to the headspace and your basket. Put a nickel on top of the prepped portafilter basket and mount it on the machine and take it out to check if the coin is pushed against the puck. If the coin does not leave any remark or very small remark your dose is not prone to puck touching the shower head and challenging (bolt type shower screw messes things here, for bolt type screw you can do the test without using a nickel).

I think as long as you don't get non-channeling shots your grind and dose adjustments are not giving you correct feedbacks.

After you get consistently proper extractions, then you can adjust grind/dose to find an yield/dose ratio and extraction time that tastes best to your liking. Temperature will also play role and as others suggested you need to time your shot start based on machines cycles. Your machine has cycles like 3minute heaters off, 20 seconds heaters on (I made up numbers). These cycle times will settle on constant values after your machine is fully warmed up. You get the hottest Temperatures if you start your shots at the timing that you start your shot x seconds before the heaters are turned off. And the heaters keep running during the entire shot. Let's say you wait 15 seconds (5 seconds before heaters are turned off) and during the entire shot heaters keep working. If you start at 10 seconds instead of 15 you get cooler shot temperature. You can also start your shot timing after the heater are turned off but due to the deadband of the thermostats the actual temperature during the shot may drop/fluctuate more compared to when heaters are on.

suolin

Postby suolin » Jul 07, 2019, 10:02 pm

Espresso_Junky wrote:Could need new burrs to revive it to like-new again. The Rocky is quite capable as I was quite satisfied with the one I did have until a week ago.


Not keen on buying new burrs but still gonna take it apart next weekend and see what it looks like.

myso wrote:[a lot of stuff]


Looking for the flat shower screen upgrade in Canada but it seems hard to find. It's 28 bucks in the states and over 60 here. I might just bite the bullet...

But you should know that based on your write-up I made myself a funnel out of a cut up club soda can and gave WDT a shot and holy crap what a difference it makes! I've achieved shot consistency at exactly 18 grams and 25 seconds. Now it still is too sour for my taste and I'm literally grinding just one step past true zero on the Rocky (so clearly there are other issues that I need to look into) but I've never before had the used puck slide out of the pf so easily. Zero channeling either. I'm happy, getting somewhere :D

kc2hje
Supporter ♡

Postby kc2hje » Jul 08, 2019, 2:42 pm

Jasper_8137 wrote:Maybe a grinder issue. I really struggled with my Rocky - it always seemed that my grind was too coarse or too fine due to the stepped adjustment.


I 2nd this and its a shame as the Rocky has great "bones" but the steps are huge I would often grind about 1/2 the dose at say 6 and the other 1/2 at 5.